Research that does not offer the prospect of direct benefit and has more than a minor increase over minimal risk is restricted in children. The concerns about enrolling adolescents in such research are often related to their comprehension of the risks and whether their decision to participate is voluntary. The objective of this project is to describe the experience of using decision monitoring in a gene transfer trial in adolescents with cystic fibrosis. Decision monitoring consisted of a phone call to 26 subjects (including 16 adolescents) 1-4 days after the consent form was signed to assess their comprehension and voluntariness. However, it is not known if this process was useful or effective. The current project will collect preliminary information from the participants in this trial at the seven sites where the study was conducted. These participants included the subjects, their parents (if adolescents), the decision monitors, the research coordinators, and the investigators. The study will involve 30-minute semi-structured telephone interviews with all willing participants. The goal of this project will be to develop a prospective study of a related intervention.